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Purpose Transport distraction osteogenesis, a kind of bone lengthening, has been used to reconstruct missing bones and soft tissues in a segmental deformity. The authors investigated the applicability of this technique to the arthroplasty of temporomandibular joint (TMJ) with an internal distraction appliance.Materials and Methods A 15 mm ascending ramus and TMJ including its disc was extirpated in 42 white rabbits (3.0 kg weight). After, a L-osteotomy was performed from the anterior border of the coronoid process to the posterior border of the mandible, an internal distraction appliance was applied. The transport disc was advanced 0.9 mm per day for 14 days. Another 24-week period, has passed after the completion of the lengthening. During this period, the rabbits were sacrificed at intervals.Results Eight weeks after the completion of the lengthening, the distraction gap between the adjacent preexisting mandible was indistinguishable in X-ray photographs. New bone and a large amount of cartilage were observed between the distraction gap. The new bone was also observed at the leading edge of the Transport disc. This bone seemed to regenerate froth the surrounding periosteum.More than 8 weeks after the completion of lengthening, the mature cortical bone was reconstructed. A collagenous structure like a cap was formed over the leading edge. This cap may substitute for an articular disc. The new bone has remodeled and resembled the condylar head.Conclusion The bone transport technique is promising for the reconstruction of TMJ.